Seal for floating tank roofs



June 1, 1937. J. H. WIGGINS 2,082,194

SEAL FOR FLOATING TANK ROOFS Filed April 12, 1934 Patented June 1, 1937 UNITED STATES PATENT OFFICE.

SEAL FOR FLOATING TANK ROOFS John H.-Wiggins, Tulsa, Okla.

Application April 12, 1934, Serial No. 720,158

6 Claims.

This invention relates to seals for floating tank roofs, my present application being a continuation in part of my pending application for Patent Serial No. 436,217, flled March 15, 1930.

Oneobject of my present invention is to reduce the cost, reduce the number of parts and simplify the fabrication and installation of the so-called Wiggins type seal for floating tank roofs.

Another object is to provide a novel hanger structure or shoe supporting means for floating tank roof seals, that is inexpensive, reliable in operation, and of such design that it can be fabricated at a factory and then shipped as a unit to the field and mounted quickly and accurately on the floating tank roof on which it is used.

I have herein illustrated my invention embodied in a seal for a floating tank roof of the pontoon type, but I wish it to be understood that my invention is applicable to and capable of use with floating tank roofs of the so-called pan type.

Figure 1 of the drawing is a fragmentary top plan view of a floating tank roof equipped with a seal constructed in accordance with my present invention.

Figure 2 is an enlarged fragmentary vertical sectional view, taken on the line 2-4 of Figure 1, looking in the direction indicated by the arrows.

Figure 3 is a vertical sectional view, taken on the line33ofFigure2. Y

Figure 4 is a horizontal sectional. view, taken on the line 4-4 of Figure 2, illustrating one of the vertically-disposed fabric elements used to close the gap between adjacent shoe members; and.

Figure 5 is a fragmentary perspective view, illustrating the means that I prefer to use for connecting the fabric elements to the parts of the structure with which they co-act.

The Wiggins floating tank roof seal that is now in extensive use, comprises a vertically-disposed,

annular metal shoe of considerable height, arranged substantially parallel to and in sliding engagement with the side wall of the tank, and joinedto the floating tank roof usually by a fabric element that serves as a closure for the space between said shoe and floating roof. The common practice for many years has been to construct said annular shoe from a relatively large number of vertically-disposed shoe members (usually about 3 ft. in length) made of stiff or heavy flanged metal plates, joined together by vertically-disposed fabric elements that close the gaps between adjacent shoe members. on account of the relatively large number of shoe memtween and connected by. two gas-tight joints tothe two shoe members at the opposite sides of the gap which the fabric element closes. Moreover, as the shoe members were made of relatively heavy or thick metal plates whose upper and lower edge portions were flanged or bent inwardly, it was impossible for the individual shoe members to flex circumferentially intermediate their ends, or flex in such a way as to accurately conform to the curvature of the side wall of the tank.

The seal herein described which constitutes my present invention, departs radically from the previous commercial practice in constructing Wiggins tank roof seals, in that it comprises an annular shoe constructed in such a way as to comprise a relatively small number of segmental sections or shoe members, each of which is substantially arc-shaped and capable of flexing circumferentially intermediate its ends, suiflciently to conform to or adapt itself to the curvature of the side wall of the tank, even a side wall that is slightly out of round or not of truly cylindrical shape. by substantially increasing the length of the shoe members or segmental portions of the shoe and making them in such a way that the beveled or inwardly bent upper and lower edge portions of same, used to guide the shoe over protuberances or irregularities on the inner face of the side wall of the tank, will not retard or interfere with the circumferential flexing of said shoe members. Due to the fact that the inwardly directed means on the upper and lower edge portions of the shoe members are constructed in such a way that the shoe members have only a single curvature, said shoe members may be formed from metal plates that are either of conventional thickness or lightor or thinner than has heretofore been the custom.

In the accompanying drawing which illus-' This highly desirable result is attained of the roof A is a seal that comprises an anbasic principles or distinguishing characteristics basicprinciples or distingushing characteristics of the Wiggins tank roof seal, i. e., it is of considerable height or depth and has a substantially vertically-disposed portion of considerable area arranged in parallel or substantially parallel relation to the side wall 2 of the tank. Said annular shoe is made of relatively thin or light gage metal plates, and in a seal for large-sized tanks the annular shoe will comprise only a small fraction of the number of shoe members of a conventional Wiggins tank roof seal. Each shoe member is provided with a guiding means that insures the shoe member sliding freely over projections, protuberances or irregularities on the inner face of the side wall of the tank, but said guiding means is so constructed that it will not retard or prevent the shoe member from flexing circumferentially intermediate its ends, suiiiciently to conform with considerable accuracy to the curvature or shape of the side wall of the tank.

Preferably, said annular shoe is made up of a plurality of relatively long,v circumferentially flexible shoe members B, each of which comprises a vertically-disposed portion of arc shape in horizontal section, that is disposed in parallel or substantially parallel relation to the side wall of the tank. The number of said shoe members will vary according to the diameter of the tank, but said shoe members will be made of such length that each of same will have suflicient inherent flexibility (circumferentially) to cause it to follow the curvature or outline of the tank side wall. On a large tank of great storage capacity, say, for example, a tank having a diameter of approximately 100 ft., each shoe member B will be approximately 30 ft. long, or, in other words, about ten times as long as the shoe members heretofore used in Wiggins tank shoe seals. The gap or gaps formed by the space or spaces between the ends of the shoe members B are closed by vertically-disposed fabric elements 3 which are attached to the ends of the shoe members, preferably in a manner hereinafter described. While I have stated that the shoe members B are usually made about 30 ft. in length, this is not essential. The point that I desire to emphasize is that my present invention makes it practicable to use any length of shoe member that can be handled conveniently in the operation of erecting or installing the seal. In fact, on small-sized tanks, the annular shoe of the seal may consist of a substantially continuous, circumferentially flexible structure provided with a single gap in which a vertically-disposed fabric element is arranged to seal or close said gap. In order to guide the shoe members B over the inner face of the side wall of the tank and prevent said shoe members from catching on projections or protuberances on said side wall, I provide the upper and lower end portions of said shoe members with beveled or inwardly bent portions 4, as shown in Figure 5. Unless means were provided to overcome the stiffening efiect produced by said inwardly bent portions 4, the shoe members would not flex circumferentially intermediate their ends, as previously described. Accordingly, I provide the flanged or inwardly bent portions 4 of each shoe member B with a plurality of vertically-disposed slits, notches or saw kerfs 4, as shown in Figure 5, that do not interfere with the proper functioning of said guiding p i s but which efisei i v nt mounted on the floating roof A and combined with the shoe members B in such a way, that said shoe members will be maintained in parallel relationship with the side wall 2 of the tank, and movement of said shoe members inwardly, towards the floating roof, will be resisted by a resilient means which tends to hold the floating roof and the annular shoe in approximately con-- centric relationship. The specific number of hanger structures that is employed for each shoe member may vary, but I prefer to space the hanger structures about 3 ft. apart so as to provide an adequate supporting means for the annular shoe that contacts the vertical side wall of the tank. In the form of my invention herein illustrated each of the hanger structures just referred to comprises a substantially elbow shaped lever or hanger C pivotally mounted at 5 on a pair of vertically-disposed uprights 6 in such a way that one arm I of said hanger will project downwardly and outwardly towards the side wall 2 of the tank, and thus permit the lower end of said arm to be attached to its shoe member B by a pivot or pintle pin 8 which is located at a point considerably below and on the outside of the pivot 5 of the hanger. As shown in Figure 3, the pivot or pintle pin 8 which joins the shoe member to the lower end of the arm I of the hanger is located near enough to the upper edge of the shoe member to assure the shoe member naturally assuming a substantially vertical or upright position with the lower end of same engaging the side wall of the tank. The other arm 1 of the hanger projects inwardly in a substan tially radial direction, towards the center of the floating roof A, and a spring 9 is attached to the inner end of said arm 1* in such a manner that when the downwardly-projecting arm I of said hanger swings outwardly towards the side Wall of the tank, the tension of said spring 9 will be decreased, and when said downwardly-projecting arm I swings inwardly, towards the floating roof, the tension of said spring 9 will be increased. Accordingly, in a floating tank roof seal equipped with hanger structuresof the design above described, there will be a natural tendency for the annular shoe and the floating roof to remain in substantially concentric relationship, with the shoe members B in a vertical position in snug engagement with the side wall of the tank. No stops or abutment devices are required to limit the outward movement of the shoe members, i. e., movement away from the floating roof. Instead, the springs 9 are so arranged that the tension of same is increased by movement of the shoe members inwardly towards the floating roof, and hence, such inward movement of the shoe members causes the springs 9 to function to restore the approximately concentric relationship between the shoe members and the floating roof, and hold the roof properly centered with relation to the side wall of the tank.

The pair of uprights 6 on which each hanger rights I are spread or flared slightly, as shown.

in Figure 2, and if desired, they may be combined with inclined braces ll. Said upri8hts or supports 0 and the inclined braces II that cooperate with same, are preferably welded to the peripheral portion of the floating roof, as, for example, to the top side of the pontoon i, but said uprights may be connected in any other suitable way to the floating roof. Whatever method is employed to attach the uprights 6 to the floating roof, one decided advantage of the hanger structure above described is that it may be constructed as a unit in a factory and then shipped in an assembled state to the .point where it is to be used and then mounted quickly and accurately on the floating roof. As shown in Figure 3, the lower end of the spring I of each hanger structure is attached to one of the uprights 6 of the structure.

A substantially annular-shaped fabric element 3' is attached to the peripheral edge of the floating roof and to the annular shoe formed by the shoe members B, so as to form a closure for the space between the floating roof. and the side wall of the tank. The connecting means used to join said fabric element 3' to the metallic parts with which it co-acts, preferably comprises substantially horizontally-disposed metal clamping rods or bars Ii and II superimposed upon or arranged in engagement with the top side of said fabric element 3* adjacent the inner and outer edges of same, a plurality of substantially hookshaped devices I! and I! on the top side of the pontoon i and on the inner sides of the shoe members B, disposed in overlapping relation with said rods II and iiand retaining wedges l3 and I3 driven between said rods and hookshaped devices, as shown clearly in Figure 5, the hook-shaped devices I2 and I! being welded or connected in any other suitable way to pon-- toonl and to the shoe members B. The means that is used to connect the vertically-disposed fabric elements I to the ends of the shoe members B is of substantially the same construction and comprises vertically-disposed clamping rods or bars li arranged in engagement with said fabric elements 3, so as to clamp-each fabric element 3 securely to the pair of shoe members B with which it co-acts, horizontally-disposed, hook-shaped devices li on the shoe members that overhang or lap over said clamping rods, and wedges l3 driven between said clamping rods and hook-shaped devices, so as to securely retain the clamping rods in position. The annular fabric element 3' is connected to the upper ends of the vertically-disposed fabric elements 3 in a conventional manner, so as to produce gas-tight joints between said parts, and some suitableadhesive or sealing substance is also preferably applied to the surfaces of the metal parts to which the fabric elements are clamped.

Having thus described my invention. what I claim as new and desire to secure by Letters Patent is: 1

1. The combination of a floating tank roof. an annular seal shoe surrounding said roof and adapted to contact the side wall of the tank, and hanger structures on said roof that sustain said shoe, each of said hanger structures consisting of a self-contained or assembled unit made up of a vertically-disposed standard arranged entirely within the marginal limits of the floating roof, a rockable hanger pivotally connected to the upper end of said standard at a point within the peripheral edge of said floating roof, and a spring combined with said hanger and support for maintaining the shoe in substantially concentric relation with the roof.

2. The combination of a floating tank roof, an annular seal shoe surrounding said roof and adapted to contact the side wall of the tank, and hanger structures on said roof that sustain said shoe, each of said hanger structures comprising a pair of vertically-disposed standards adapted to be mounted on and connected to the roof at a point within the marginal edge of said roof, a rockable hanger embraced by said supports and pivotally connected to the upper ends of same, and a spring attached to said hanger and disposed so as to resist movement of the shoe, inwardly towards the roof.

3. A seal for floating tank roofs, comprising an annular metal shoe, arranged vertically in substantially parallel relationship with the inner face of the side wall of the tank, said shoe comprising segments which areof substantial length and of single curvature, to permit said segments to flex intermediate their ends so as to follow the curvature-of the side wall of the tank.

4. A seal for floating tank roofs of the kind described in claim 3, in which the segments of the shoe have spaced, inwardly directed means on their upper and lower edge portions, for guiding said segments over projections or protuberances on the side wall of the tank.

5. A seal for floating tank roofs of the kind described in claim 3, equipped with flexible seals for the Joints between the vertical edges of the segments of the shoe.

6. The combination of a tank, a floating roof for said tank, and a seal for said floating roof, said seal comprising an annular metal shoe, arranged vertically in substantially parallel relationship with the inner face of the sidewall of the tank, the said shoe comprising segments of substantial length and of single curvature to permit said segments to flex intermediate their ends to follow the curvature of the side wall ofthe tank and a flexible sealing means between the inner face of said shoe and the outer edge of the floating roof.

JOHN H. WIGGINB.

sentiments or} connscrron.

Patent no. 2,082,194. June 1, 1937.

gonna. wmemsl.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, first column, line 1-2} strike out the syllable and words "anbasic principles or distinguishing characteristics" and insert instead annular metal shoe which embodies one of the; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office:

Signed and sealed this 20th day of July, A. D. 1937.

Henry Van Arsdale (Seal) Acting Commissioner of Patents. 

